Preheat oven to 375°F.

Put the almonds and the cup of sugar into the bowl of a food processor, add the almond extract, if using, and grind into a fine meal, about 2 minutes.

While the processor is running, add the egg whites and process for about 30 seconds.

Scoop out level tablespoons of the batter onto baking sheets that have been lined with baking parchment or silicone sheets.

Bake for 18-20 minutes. Rotate the sheets from front to back and from top to bottom halfway through baking. The cookies will puff up a bit, the tops will be dry, and the edges will have just begun to turn brown.

Using a wide metal spatula, slide each cookie off and unto a cooling rack.